The lubrication of bone joints is a subject of ongoing medical research. two bones connected at a joint do not touch. the bones are covered in articular cartilage, and are surrounded by lubricating synovial fluid. rheumatoid arthritis results in overproduction of synovial fluid, swollen joints, and difficult and painful movement. other joint disorders degrade the synovial fluid, directly increasing the friction between the bones, resulting in painful motion.

part a

to measure the effective coefficient of friction in a bone joint, a healthy joint (and its immediate surroundings) can be removed from a fresh cadaver. the joint is inverted, and a weight is used to apply a downward force

the answer is b i think

there is no correct list among the choices you've provided.

the list might look something like this:

-- baby human

-- piccolo

-- flute

-- soprano singer

-- trumpet

-- tenor singer

-- trombone

-- baritone singer

-- baritone horn

-- bass singer

-- tuba

since i had to make up the list myself, i made it easy on myself, and i didn't try to shuffle the string instruments and woodwinds into it too.

305.7

explanation:

density =m/v

density =917/3.00

density = 305.

approximately = 305.7

in four significant figures

the best answer for these questions would be:

1.            c. is smaller

2.            d) concrete operational

3.            b) interaction with the environment – the children interact with their environment can them learn more.

4.            a) parents who reason openly with children can limit a child’s cognitive ability.